When I saw that there was a battery extender out for my Zaurus and Axim I
decided I had to buy one and give it a try. My hopes were that it would greatly
increase the Wardriving abilities of my Zaurus 5500, and to cut to the chase it
certainly does. Basically, the way these battery extenders work is by filling
them up with rechargeable AA batteries and hooking the extender to the external
power input of your PDA. The device is not complicated and you might be able to
make one yourself with a few parts from an electronics store.

I did some surfing around on
Froogle for the cheapest price and I ended
up buying it from from Semons & Co. Inc (
http://store.yahoo.com/semsons-inc/pdabatexpocp.html ) for $6.99 plus
shipping and handling. When it was first shipped someone or something had opened
the envelope it came in and the 1600 mAH Capacity "AA" NiMH batteries I ordered
with the extender had fallen out, but a quick email to Semons and they
resent the batteries. Semons service was good, I can recommend them and would
buy from them again.

Once all of the stuff I ordered
got to me I went about testing the equipment to see if the extender increased
the battery life significantly. Here is a rough timeline of my tests.

10:39 am - Plugged the extender into my fully charged Zaurus and
started to run Kismet 3.1 using my Ambicom WL1100C-CF 802.11b Wi-Fi card. The
back light was set to half of max brightness and to turn off after about 20
sec of not being used. The backlight would go on whenever I tapped the screen
to check the status.

12:08 pm - Turned the extender and the Zaurus off and went to see
Jersey Girl.

3:00 pm - Turned the extender and the Zaurus back on and started
running Kismet again, I had to reset the Zaurus a few times because I kept
filling up my root partition with data files from Kismet and other apps I was
running.

5:00 pm - I notice the internal battery reading was at about 75%. The
battery monitor on the Zaurus does not always give you an "on the spot"
reading, if fluctuates a lot. I though maybe the AA batteries in the extender
had been used enough to where they had become a load themselves, so I unhooked
the extender from the Zaurus and the internal battery took over. The reading
of the internal battery jumped up at this point to 100%.

7:00 pm - The internal battery got down to about 12% so I hooked the
extender back up. It seems that the Zaurus 5500 can run for about 2hrs on the
internal battery while using a Wi-Fi card in RF monitoring mode. I got my
Zaurus used so your mileage may vary.

9:00 pm - I got bored with the test, so I set the back light to full
brightness and set it to never turn off. The battery reading actually jumped
up! As I inferred before, don't trust what the battery reading says.

9:15 pm - If memory servers, I looked down at the Zaurus at 9:14 pm
and it was still on, but when I looked back at 9:16 pm it was off. At this
point I had to take it upstairs and put it on a charger.

Summary: The extender let
me take the battery life from 2 hours to about 7 hours and 45 minutes. That's
one hell of a wardrive/warwalk. If you want to use the Zaurus as a mobile hack
tool get an extender.